CN207269198U - A kind of high-gain Double-input direct-current converter based on capacitance series parallel structure - Google Patents

Abstract

A kind of high-gain Double-input direct-current converter based on capacitance series parallel structure is the utility model is related to, includes two input sources, two inductance, two power switch pipes, one three switching capacity connection in series-parallel unit, an output diode, an output filter capacitor and load resistance.Three switching capacity connection in series-parallel units include three switching capacities and three diodes, by the break-make of controlling switch pipe, effectively realize the symmetrical connection in series-parallel discharge and recharge of capacitance, mainly include two processes：C₂、C₃Parallel discharge gives capacitance C at the same time₁Charging；C₁Electric discharge gives capacitance C at the same time₂、C₃Serial connection charge.This topological structure simple symmetric, switching device voltage stress is small, two-way input source is provided which the voltage gain of 2 times of traditional Boosts, realize the high boosting inverter of two input sources, and control simple and flexible, by controlling two-way duty cycle to realize the control of two-way input current and output voltage, that is, realize the flexible allocation of each input source power and the maximal power tracing of new energy.

Description

A kind of high-gain Double-input direct-current converter based on capacitance series parallel structure

Technical field

A kind of DC-DC converter is the utility model is related to, specifically a kind of height based on capacitance series parallel structure Gain Double-input direct-current converter.

Background technology

The getting worse of the problems such as with energy crisis and environmental pollution, renewable, clean new energy receive much concern, its Middle photovoltaic cell capable of generating power is most widely used.However, photovoltaic cells are larger by environment, weather and regional impact, its electricity sent Power is unstable, discontinuous, it is necessary to form joint electric power system, guarantee power supply reliability with reference to energy-storage units such as storage batteries.

Traditional new energy joint electric power system, it is defeated that every kind of energy form by respective booster converter becomes direct current Go out, be connected in parallel on public high voltage dc bus, then by gird-connected inverter to power grid or load supplying, its is complicated, into This is higher.To simplify circuit structure and reducing cost, repeated use of device rate is improved, can be replaced with a multi-input direct current converter Multiple single input DC converters.In addition, in monophase system, the direct current of network voltage 220VAC, then gird-connected inverter Pressure is about 380VDC.And the output voltage of photovoltaic cell and storage battery is relatively low, generally 25V~45V, far below gird-connected inverter Required DC voltage, traditional Boost will be inapplicable.Therefore, new energy combine electric power system in, it is desirable to it is straight Current converter must simultaneously have high-gain and multi input ability.

The content of the invention

The purpose of this utility model be to provide that a kind of topological structure is simple, control method is simple and with high voltage gain, Switching device voltage stress is small, and flexible allocation respectively inputs the high-gain Double-input direct-current converter of source power.

To achieve these goals, the utility model adopts the following technical solution：It is a kind of based on capacitance series parallel structure High-gain Double-input direct-current converter, it is characterised in that including two input source U₁、U₂, two inductance L₁、L₂, two power open Close pipe S₁、S₂, a three switching capacity connection in series-parallel units, an output diode VD_o, an output filter capacitor C_oAnd load Resistance R；

The three switching capacities connection in series-parallel unit includes three switching capacity C₁、C₂、C₃With three diode VD₁、VD₂、 VD₃, its connection relation is capacitance C₁Cathode meet capacitance C₂Cathode and diode VD₁Cathode, capacitance C₂Anode connect two poles Pipe VD₂Anode and diode VD₃Cathode, diode VD₁Anode meet diode VD₂Cathode and capacitance C₃Cathode, two Pole pipe VD₃Anode meet capacitance C₃Anode；

First inductance L₁Input terminate the first input power U₁Cathode, output termination switching tube S₁Drain electrode and capacitance C₁Anode, switching tube S₁Source electrode meet the first input power U₁Anode；Second inductance L₂Input terminate the second input power U₂Cathode, output termination switching tube S₂Drain electrode and capacitance C₃Anode, switching tube S₂Source electrode meet the second input power U₂'s Anode, capacitance C₁Cathode meet output diode VD_oAnode, diode VD_oCathode meet output capacitance C_oCathode and negative Carry the input terminal of resistance R；First input power U₁Anode meet the second input power U₂Anode and output capacitance C_oAnode and The output terminal of load resistance R；

Switching tube S₁And S₂Driving phase staggers 180 ° successively, i.e., using Interleaved control strategy, duty cycle is respectively D₁、D₂, And 0.5 is all higher than, and under the control mode, output voltage U during stable state_o, capacitance C₁、C₂、 C₃Voltage be respectively：

Output current I during stable state_oWith inductive current average value I_L1、I_L2Relation be：

By controlling duty cycle D₁、D₂To control the distribution of two-way input ource electric current.

Compared with prior art, the utility model has the advantages that：

1) the utility model topological structure is simple, and effective charge and discharge of capacitance is realized by the connection in series-parallel connection of switching capacity Electricity, there is no coupling inductance and transformer, volume and cost reduction；

2) two-way input source is provided which the voltage gain of 2 times of traditional Boosts, realizes the height of two input sources Boosting inverter；

3) voltage stress of switching tube and diode is much smaller than output voltage, can use the switching tube and two of low-voltage-grade Pole pipe, reduces cost and conduction loss；

4) convertor controls simple and flexible, by controlling two-way duty cycle to realize two-way input current and output voltage Control, that is, realize the flexible allocation of each input source power and the maximal power tracing of new energy.

Brief description of the drawings

Fig. 1 is a kind of high-gain Double-input direct-current converter circuit structure based on capacitance series parallel structure of the utility model Figure；

Fig. 2 is the key operation waveforms figure of the utility model converter；

Fig. 3 is equivalent circuit when the utility model converter is operated in switch mode 1；

Fig. 4 is equivalent circuit when the utility model converter is operated in switch mode 2；

Fig. 5 is equivalent circuit when the utility model converter is operated in switch mode 3；

Fig. 6 is equivalent circuit when the utility model converter is operated in switch mode 4.

Embodiment

The utility model is described in further detail with reference to the accompanying drawings and detailed description.

A kind of as shown in Figure 1, high-gain Double-input direct-current converter based on capacitance series parallel structure, it is characterised in that Including two input source U₁、U₂, two inductance L₁、L₂, two power switch tube Ss₁、S₂, a 3 switching capacity connection in series-parallel units, One output diode VD_o, an output filter capacitor C_oWith load resistance R；

The three switching capacities connection in series-parallel unit includes three switching capacity C₁、C₂、C₃With three diode VD₁、VD₂、 VD₃, its connection relation is capacitance C₁Cathode meet capacitance C₂Cathode and diode VD₁Cathode, capacitance C₂Anode connect two poles Pipe VD₂Anode and diode VD₃Cathode, diode VD₁Anode meet diode VD₂Cathode and capacitance C₃Cathode, two Pole pipe VD₃Anode meet capacitance C₃Anode；

First inductance L₁Input terminate the first input power U₁Cathode, output termination switching tube S₁Drain electrode and capacitance C₁Anode, switching tube S₁Source electrode meet the first input power U₁Anode；Second inductance L₂Input terminate the second input power U₂Cathode, output termination switching tube S₂Drain electrode and capacitance C₃Anode, switching tube S₂Source electrode meet the second input power U₂'s Anode, capacitance C₁Cathode meet output diode VD_oAnode, diode VD_oCathode meet output capacitance C_oCathode and negative Carry the input terminal of resistance R；First input power U₁Anode meet the second input power U₂Anode and output capacitance C_oAnode and The output terminal of load resistance R；

As shown in Fig. 2, switching tube S₁、S₂Using Interleaved control strategy, 180 ° of difference between phase, duty cycle difference are driven For D₁、D₂, and it is all higher than 0.5.In a switch periods, there are 4 kinds of operation modes for converter.

As shown in figure 3, converter is operated in 1 [t of mode₀~t₁]：Switching tube S₁Conducting, S₂Shut-off, diode VD₁、VD₃ Conducting, diode VD₂、VD_oCut-off.Input source U₁To inductance L₁Energy storage, inductive currentLinear rise；Inductance L₂Release energy, inductance Electric currentLinear decline；Capacitance C₂、C₃Parallel discharge gives capacitance C at the same time₁Charging, current path is respectively U₂→L₂→VD₃→C₂ →C₁→S₁And U₂→L₂→C₃→VD₁→C₁→S₁.Under the pattern, variable relation is：

i_Co=-i_o

As shown in figure 4, converter is operated in 2 [t of mode₁~t₂]：Switching tube S₁、S₂Conducting, diode VD₁~VD₃、VD_o It is turned off.Input source U₁、U₂Inductance L is given respectively₁、L₂Charging, capacitance C₁~C₃Neither discharge nor charge, capacitance C_oSupplied to load Electricity.Under the pattern, variable relation is：

i_Co=-i_o

As shown in figure 5, converter is operated in 3 [t of mode₂~t₃]：Switching tube S₂Conducting, S₁Shut-off, diode VD₂Conducting, Diode VD₁、VD₃、VD_oCut-off.Input source U₂To inductance L₂Energy storage, inductive current i_L2Linear rise；Inductance L₁Release energy, inductance electricity Flow i_L1Linear decline；In t₂Moment, capacitance voltage u_C2+u_C3<u_Co, capacitance C₁Electric discharge gives capacitance C at the same time₂、C₃Charging, electric current road Footpath is U₁→L₁→C₁→C₂→VD₂→C₃→S₂, capacitance C_oPowering load.Under the pattern, variable relation is：

As shown in fig. 6, converter is operated in 4 [t of mode₃~t₄]：Switching tube S₂Conducting, S₁Shut-off, diode VD_oConducting, Diode VD₁、VD₂、VD₃Cut-off.In t₃Moment, capacitance voltage u_C2+u_C3=u_Co, capacitance C₁Start to give capacitance C_oCharging, electric current Path is U₁→L₁→C₁→VD_o→C_o(R).Under the pattern, variable relation is：

Due to C_o>>C₂=C₃,VD_oBranch equiva lent impedance is far smaller than VD₂, can obtain：

According to inductance L₁、L₂Voltage-second balance relation, can obtain：

Capacitance voltage steady-state value meets：

Obtained according to the derivation of equation：

If (t₀~t₁)、(t₁~t₂)、(t₂~t₃)、(t₃~t₄) time segment length is respectively T₁、T₂、T₃、T₄, and meet to close It is formula：T₁=(1-D₂)T_s,T₃+T₄=(1-D₁)T_s

According to capacitance C₁~C₃、C_oAmpere-second equilibrium relation, can obtain：

Abbreviation obtains：

By the distribution for controlling the i.e. controllable two-way input power power (electric current) of duty cycle.

According to the analysis of Fig. 2-6 converters operation principle and switch mode, switching tube, diode voltage stress：

Claims (1)

1. a kind of high-gain Double-input direct-current converter based on capacitance series parallel structure, it is characterised in that including two inputs Source U₁、U₂, two inductance L₁、L₂, two power switch tube Ss₁、S₂, a three switching capacity connection in series-parallel units, two poles of output Pipe VD_o, an output filter capacitor C_oWith load resistance R；

The three switching capacities connection in series-parallel unit includes three switching capacity C₁、C₂、C₃With three diode VD₁、VD₂、VD₃, its Connection relation is capacitance C₁Cathode meet capacitance C₂Cathode and diode VD₁Cathode, capacitance C₂Anode meet diode VD₂'s Anode and diode VD₃Cathode, diode VD₁Anode meet diode VD₂Cathode and capacitance C₃Cathode, diode VD₃ Anode meet capacitance C₃Anode；

First inductance L₁Input terminate the first input power U₁Cathode, output termination switching tube S₁Drain electrode and capacitance C₁It is negative Pole, switching tube S₁Source electrode meet the first input power U₁Anode；Second inductance L₂Input terminate the second input power U₂Just Pole, output termination switching tube S₂Drain electrode and capacitance C₃Anode, switching tube S₂Source electrode meet the second input power U₂Anode, Capacitance C₁Cathode meet output diode VD_oAnode, diode VD_oCathode meet output capacitance C_oCathode and load resistance R Input terminal；First input power U₁Anode meet the second input power U₂Anode and output capacitance C_oAnode and load electricity Hinder the output terminal of R；

Switching tube S₁And S₂Driving phase staggers 180 ° successively, i.e., using Interleaved control strategy, duty cycle is respectively D₁、D₂, and More than 0.5, under the control mode, output voltage U during stable state_o, capacitance C₁、C₂、C₃Voltage be respectively：

Output current I during stable state_oWith inductive current average value I_L1、I_L2Relation be：

By controlling duty cycle D₁、D₂To control the distribution of two-way input ource electric current.